The present invention relates generally to sealed power connectors for 90xc2x0 terminal assemblies and power feed attachments, such including resilient engagement capability. More particularly, the present invention is directed to an electrical terminal socket assembly and method for constructing which incorporates a substantially rectangular and compressible contact spring cage and an encircling compressible terminal sleeve for holding the spring cage in place. The contact spring cage and sealed connector assembly provides a low cost solution for a quick connect assembly and which provides both increased contact surface area between the spring cage and associated male terminal, as well as a much greater degree of torque control in assembly as opposed to prior art bolt and nut type cable connections. The present invention further discloses a 90xc2x0 sealed connection housing, which includes angled variations of the terminal socket assembly enclosed within interengaging male and female outer connecting portions, and for better insulating and sealing the electrical connections established by the socket assembly. The configuration of the rectangular spring cage has further been found to provide sufficient contact surfaces necessary for maintaining the voltage and current carrying applications associated with larger capacity battery/power sources.
Electrical connectors of the terminal socket variety are well known in the art, one primary application of which being in the automotive field for establishing connections between heavier sized output cable and components such as generators or alternators. The frictional grip imparted by the connector must be of sufficient strength to maintain firm mechanical and adequate electrical connection, yet must permit relatively easy manual withdrawal or insertion of a prong into the connector socket.
One type of known prior art electrical cable connection is the bolt-nut type electrical cable connection. A significant problem associated with such bolt and nut arrangements arises from the amount of torque which is necessary to assemble the connector and the difficult quality control issues which arise from its large scale use such as over torque, under torque and cross thread.
Most power connection systems in the relevant art include circular type terminals. For certain applications, these require a number of components and processes in their assembly. For example, in power electrical distribution systems such as in vehicle fuse boxes, part of a copper sheet is stamped and formed into a round hollow pin. Occasionally, an additional solid pin is staked onto the copper sheet. However, and if a blade terminal is utilized, the male blade is stamped (not formed like a pin) as part of the copper sheet. This assembly does not require more process stages or par like a round pin.
It has been found that power blade terminals provide a better solution for space limitation in one direction, in some applications than in utilizing round power pin terminals. Conventional power blade terminals typically include a loose spring cage within a sleeve and in which a contact length established between the spring beam and male blade is small, thus resulting in the current carry capability being relatively low. Mechanically, a good terminal system ensures a low engaging force, while establishing a high normal (perpendicular) force. This results in the higher ratio of terminal insertion force over normal force between the male and female terminals providing an overall better terminal system. The ratio of insertion force over normal force has also been found to be very low for most conventional blade terminals.
It has also been found that aftermarket sealed female connectors (plastic housings) are typically only provided for straight terminal assemblies. In order to accommodate 90xc2x0 connections, male pin or blade terminals usually are bent to right angles then mated with a straight female terminal assembly sealed inside a female connector. However, some applications do not allow or are not cost effective to bend the male terminal to 90xc2x0 angular relationship. Thus, there has not been found to be any acceptable remedy to this kind of situation, especially for any power connection systems.
In sun, the present invention lacks a power blade terminal system which provides cost effective design and optimal package space in certain applications. It has also been determined that it is important to maintain sufficient contact surface and high normal force (between the male pin and socket cage) in order to guarantee that an adequate amount of electrical current is carried through the terminal assembly, while at the same time reducing the insertion force as low as possible. A sealed 90xc2x0 female connection has also been determined to be required for certain power applications.
The present invention discloses an electrical terminal socket assembly and method for constructing which incorporates, as a subassembly of the overall socket assembly, a substantially rectangular and compressible spring cage and a supporting rectangular shaped and compressible terminal/contact sleeve for holding the spring cage in place. As previously explained, the present assembly and method for constructing provides a low cost solution for a quick connect assembly and which requires a much greater degree of torque control in assembly, as opposed to prior art bolt and nut type cable connections. The present invention is also an improvement over prior art assembly techniques which require the spring cage element to be formed in place after it is has been inserted into the corresponding sleeve component, particularly in that the present invention provides only two components and a simplified assembly process. It is further contemplated that the assembly part can be manufactured in conjunction with a fast speed progression die.
A spring cage blank has first and second extending edges and a plurality of spaced apart and angled beams extending between the edges. As disclosed in copending application Ser. No. 09/951,012, filed Sep. 14, 2001, and in a preferred variant, it is contemplated that a plurality of the spring cage blanks may be provided in spaced fashion between first and second carrier strips and which permit the blanks to be transferred in succession into an appropriate die stamping, tool punching or other suitable forming operation. As is again previously described in U.S. Ser. No. 09/951,012, it is further contemplated that such stamping or other forming operation may further include the provision of first and second spaced apart and opposing mandrels, each exhibiting a suitable exterior configuration for shouldering and forming the three dimensional rectangular configuration of the compressible spring cage.
Aspects of the rectangularly formed spring cage include the combined bending of the individual beams along their axially extending directions, combined with torsioning (or twisting) each of the beams in a direction perpendicular to their axial extending length. The suitable tool punching or die forming operations performed on the spring cage, during its transition from a blank form to a substantially rectangular and three dimensional shape, further imparts an outwardly flared and arcuate configuration to each of the spaced apart faces of the spring cage.
The contact sleeve is likewise provided in initial blank form and, upon completion of the suitable forming operations, exhibits a likewise substantially rectangular shaped three dimensional body with open interior communicated by first and second open ends. The longer sides of the rectangular shaped cage are slightly imparted to be outwardly flared and adopt an arcuate configuration relative to the sleeve. Contact tab portions extend from the rectangular encasing portion of the sleeve and, as will be subsequently described, are crimped/bent to engage extending and exposed wire end portions of an associated electrical cable.
The contact sleeve is otherwise shaped with an open interior dimension permitting easy insertion of the spring cage, upon which crimping or compressing operations are conducted for retaining the spring cage in fixed and pressure retaining fashion. Along these lines, the sleeve is typically slitted or otherwise configured so that opposing edges are separated by a specified gap and are capable of being compressingly engaged together. In a preferred variant, meshing keyed portions are defined along the slitted and gapped surface and so that, upon inserting assembly of the formed spring cage, the exterior surface of the sleeve is compressingly engaged (such as again through the employed of stamping dies or other suitable manufacturing operation) and in order to create a desired interference fit between the spring cage and the interior of the sleeve.
Additionally, linearly extending portions of the spaced apart faces of the sleeve may be collapsed inwardly to further grip and secure the interiorly held spring cage. An arcuate configuration impartial to each of the spaced apart faces of the spring cage exhibits a smaller radius than the arcuate configuration of the sleeve. The spaced apart faces of the spring cage are thus strongly compressed and therefore create a strong pressure between the spring cage and sleeve, however the spring cage is found to not collapse by virtue of the arcuate configurations of the spring cage and sleeve, and with assistance from assembly tools which hold the inside dimensions at both ends. The principle for this is similar to that of an arcuate bridge, which can withstand heavy weight from the top.
The interference fit created between the spring cage and sleeve provides the primary retaining feature of the terminal socket assembly. Additional lances may however be protruded at a transition location along a back edge of the sleeve box. The lances function as a forward stop when assembling the spring cage into the sleeve and further assist in retaining the cage inside the sleeve. Along a front insertion face of the sleeve, crimping portions may also be accommodated at lateral edge locations. The crimping portions also function as an assist in retaining the cage inside the sleeve, it again being understood that the lance and crimping feature are, at most, supplemental in retaining the cage inside the tubular sleeve and that the primary holding forces arise from the collapsing/compressing force of the sleeve about the interiorly encased spring cage.
In order to complete the electrical connection, an extending end of a male blade is secured within the interiorly hollowed sleeve and assembled spring cage. Again, angled beams are extended between the edges of the associated spring cage. The rectangularly formed spring cage includes the combined bending of the individual beams along their axially extending directions, combined with torsioning (or twisting) each of the beams in a direction perpendicular to their axial extending length. The contact length between the male blade and spring beams is toward a diagonal direction, instead of a width of a beam of conventional beam design. Therefore, the configuration of the spring cage in particular maximizes both the surface area of contact between the configured beams and the associated male blade.
With angled, curved and torsioned (or twisted) bending of each of the beams, the male blade is inserted into the spring cage, within the sleeve and deflects and twists the spring beams, instead of deflecting the spring beam only such as in conventional spring beams. In contrast, conventional beams of associated spring cages usually are not angled and/or twisted. In this fashion, it has been found to use much less force to deflect and twist the spring beams, as compared to higher forces needed to deflect spring beams in conventional spring beam designs. Also, the present design reduces the necessary insertion force of the blade pin into the spring cage/sleeve assembly; concurrent with establishing a relatively higher normal force established between the pin and cage.
During insertion of the male blade at its engaged position with spring cage-sleeve assembly, the male blade may potentially overstress the spring beams, particularly if the male blade is wiggled or bent by outside factors. Accordingly, two ribs on the top and bottom of the sleeve are protruded inwardly, such that the spring beam will be stopped by the two ribs in the event the beams are deflected a pre-specified distance. The sleeve, in any of a number of alternate variants, further includes actuable gripping portions for fixedly engaging against and securing an extending end of a cable. The gripping portions may further be configured so that the cable extends in an angular (typically 90xc2x0) relationship relative to the male blade secured to the sleeve and spring cage assembly.
Assembly configurations of the quick connect socket assembly further disclose 90xc2x0 sealed housing constructions, such as including a female housing connector, terminal position assurance, and associated seals and retainers for electrically and environmentally sealing and insulating the socket assembly and extending cables. A method to assemble a 90xc2x0 female terminal assembly is also disclosed in the present invention. After the interfacial seal is assembled to connector housing, the interfacial seal retainer is ultrasonically welded to the connector housing at the connector manufacturer. The connector housing sub-assembly, terminal position assurance, grommet, and grommet retainer are then shipped to the wire and harness manufacturer for further assembling. In a first assembly step, a grommet retainer and grommet are slidably engaged onto a cable. Second, the cable is bent and pushed through a female housing connector. In a third step, grip portions of the female terminal assembly are crimped and the female terminal-cable assembly is retracted such that female terminal seats at the proper position inside the female housing connector. A terminal position assurance is assembled, and, finally, the grommet and grommet retainer are assembled upon the female housing connector to complete the assembly.
A method for assembling the spring cage of the terminal socket assembly is also disclosed, substantially according to the afore-described assembly, and includes the steps of providing at least one spring cage blank with first and second extending edges and a plurality of spaced apart and angled beams extending between the extending edges and forming the spring cage blank into the substantially rectangular shaped configuration and in which the angled beams are arranged in the combined angled/curved/torsioned manner, the extended edges of the beams being formed in an arcuate configuration. Additional steps include forming/providing the substantially rectangular shaped and interiorly hollowed sleeve with a slightly arcuate configuration on both the top and bottom of the sleeve, insertably assembling the formed spring cage into an open end of the sleeve, and compressingly actuating the sleeve in biasing fashion about the spring cage so that it can biasingly engage an extending end of the male blade in which the spring beams are over stress protected by the two ribs of the sleeve; concurrently, the sleeve grips an extending end of the cable at a further location in order to electrically communicate the male blade with the cable.